外贸函电里面的一道题目,答案有争议,求真相帝

问题描述:

外贸函电里面的一道题目,答案有争议,求真相帝
All the shipping space for June shipment_____,we can not but ask you to extend the date of shipment till July 31.2005..
A:BOOKED UP B:BEING BOOKED UP
两个答案该如何取舍呢?有具体解释更佳,

应该选“B”吧,"be booked up"意为“预订一空”,同时也符合独立主格结构.